[PATCH] md: Fix badness in sysfs_notify caused by md_new_event
From: NeilBrown <neilb@suse.de>
If an error is reported by a drive in a RAID array (which is done via
bi_end_io - in interrupt context), we call md_error and md_new_event which
calls sysfs_notify. However sysfs_notify grabs a mutex and so cannot be
called in interrupt context.
This patch just creates a variant of md_new_event which avoids the sysfs
call, and uses that. A better fix for later is to arrange for the event to
be called from user-context.
Note: avoiding the sysfs call isn't a problem as an error will not, by
itself, modify the sync_action attribute. (We do still need to
wake_up(&md_event_waiters) as an error by itself will modify /proc/mdstat).
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index ec80291..f19b874 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -167,6 +167,15 @@
}
EXPORT_SYMBOL_GPL(md_new_event);
+/* Alternate version that can be called from interrupts
+ * when calling sysfs_notify isn't needed.
+ */
+void md_new_event_inintr(mddev_t *mddev)
+{
+ atomic_inc(&md_event_count);
+ wake_up(&md_event_waiters);
+}
+
/*
* Enables to iterate over all existing md arrays
* all_mddevs_lock protects this list.
@@ -4149,7 +4158,7 @@
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
- md_new_event(mddev);
+ md_new_event_inintr(mddev);
}
/* seq_file implementation /proc/mdstat */